Fabrication of microcoil/microsprings for novel chemical and biological sensing

This paper reports the fabrication of a novel microsensor structure using inductively coupled plasma source (ICP) dry etching process. The novel sensor is based on a SiO2/Si/SU-8 trilayered microcoil/microspring structure. The diameter of the microcoil was approximately 600 μm. The ICP process and SU-8 exposing time are discussed. The SiO2 layer can be conveniently modified according to typical silica surface modification procedures. The microcoils could expand or contract upon interaction of specific species in the environment with receptors on the SiO2 surface due to the surface stress or energy applied on the SiO2 surface of the microcoil. This microcoil device may be widely used in biomedical and chemical sensing applications.